VPNs typically provide cost-effective means for conducting voice and data communications between, for example, corporate data centers, remote offices, mobile employees, customers, suppliers, and business partners. In general, a VPN is a private network configured within a public network, such as a service provider's network or the Internet. The VPN of a given customer appears privately dedicated to that customer, when in actuality the customer's VPN shares the same physical backbone with the VPNs of many other customers.
Implementing a Multiprotocol Label Switching (MPLS)-based VPN generally requires the distribution of certain routing information between provider edge (PE) routers of the service provider's network. A commonly used inter-domain routing protocol for exchanging such routing information is the Border Gateway Protocol, or BGP. For example, using BGP messages, PE routers exchange VPN routes with customer edge (CE) routers and with other routers in the service provider's network.
Typically, a user needs to manually configure network monitoring tools for all VPN sites. While this will work for small numbers of VPNs, this solution is not scalable and may be difficult to implement or administer for large number of VPNs.